Truing device



March 11, 1930. H. w. HOLMES 1,750,175

TRUING DEVICE Filed Aug. 14. 1926 Harold W/olme Patented Mar. Il, 193() y N UNITED staresk PATENT 'OFFICE HAROLD W. HOLMES, OF DETROIT, MICHIGAN, ASSIGNOR, EBY MESNE ASSIGNMENTS, TO CINCINNATI GRINDERS INCORPORATED, F CINCINNATI, OHIO, .A CORPORATION 0F OHIO TRUING :DEVICE Application led August 14, 1926. Serial No. 129,184.

This invention relates to grinding machines and more particularly to devices for truing or shaping the surface of the abrasive wheel or wheels in grinding machines.

It is an object of the present invention to provide a grinding machine having a truing `device which is of simple construction andvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts as will be exemplified in the structure to be hereinafter described and the scope of the application of which will be indicated in the following claims.

1n the accompanying drawing in which is shown one of the various possible embodiments of this invention,

Fig. 1 is a side elevational view partly in section of a portion of a grinding machine embodying the invention; y

Fig. 2 is a front elevational view of the same;

Fig. 3 is a sectional detail view taken substantially as indicated by the line 3---3 in Figure 2 of the adjustable mounting for the forming bar shown in Figs. 1 and 2; and

Fig. 4 is a sectional view taken along the line 4-4 of Fig. 2.

The machine shown in the drawing includes a grinding wheel 10 mounted upon a spindle held in suitable bearings upon the main frame (not shown) of the machine. A guard 11 is mounted upon the frame of the machine so as to extend around a portion of the wheel and is provided with a pair of pads 12 and 13 having flat surfaces for supporting parts of the truing mechanism. A bracket 14 is secured upon the pad 12 by screws 15 and is provided with a pair of upwardly extending arms 16 and 17 each of which is provided with a bearing 18 for supporting a hollow cylindrical supporting member 19 which is adapted to turn freely therein.

An arm 20 is provided with bearings 21 and 22 which slidably embrace the supporting member 19 andthe arm 20 is constructed relatively heavy and is provided with a weight 25 so that the follower 26 (Figure 1) which isinounted in the arm 20, may be held with considerable force against the guiding surface of a forming bar 27. One end of the bar is mounted to turn about a shaft 28 in a bracket 29 held upon the pad 13 by screws 30. The bracket 29 is provided with a cylindrical hole 31 adapted to receive for slidable engagement therewith a cylindrical block 32 provided with a flat inclined surface 33 (Fig.

The block 32 is provided with a screw 34 extending from one end thereof and adapted to engage a knob 35 which rests against a shoulder 36 on the bracket 29 and is held thereagainst by a lei-shaped washer 37 tting 1n a groove 33 in the knob and secured to the bracket 29 by screws 39. lhe hole 31 is provided with an opening 40 to permit the bearing 41 projecting from the free end of the forming bar 27 to engage the inclined surface 33 upon the cylindrical block 32. An inclined surface 42 (ligure 4) is provided upon the forming bar 27 near its free end and upon the side opposite the cylindrical block 32. The bearing 41 upon the forming bar is held in a desired position against the inclined surface 33 upon the block 32 by a cone pointed screw 43 passing through the bracket 29 and engaging the inclined surface 42 to hold the forming bar against swinging outwardly. The knob 35 is provided with graduations 44 (Figure 2) so that the guiding surface 45 of the forming bar may be accurately adjusted in a desired angular position relative to the axis of the abrasive wheel.

The lower end of the arm 20 is provided with a cylindrical portion 47 having a hole 48 to receive a cylindrical slide 49 which is slidably mounted therein and held against rotative movement by a dog point screw 50 in the cylindrical portion 47 and adapted to engage a groove 51 in the slide 49. A holder tegral part of the screw 57 and is ada ted tol the bushing 59 to prevent axi movement of the screw 57. A star shaped knob 63 is mounted upon the screw 57 and is prevented from turning relative thereto by a key 64 secured in the screw 57 and ada ted to engage a groove 65 in the knob 63, an is held against the end of the bearing 59 by a nut 66 upon the end of the screw. A scale 67 is provided upon the knob 63 cooperating with an index mark at 68 on the bearing 59 so as to insure accurate adjustment of t e dresser 53 relative to the abrasive wheel in a direction toward and away from the axis thereof.

The arm is moved upon the c lindrical support 19 Figure 2) in the direction of the axis thereo by a screw 70 adapted to enge a nut 71 within the supporting member 19, the supportin member 19 being held against turning re ative to the arm 20 by a pin 72 passing through the bearinn22 through the wall of the hollow'cylin `cal member 19 and enging the nut 71. A slot 73 is provided in e supporting member 19 to jlrovide a free pway for the in 72 as t e arm 20 is moved axially of its cy dricalsupport 19. The screw 70 is mounted for rotation within a bearing bushing 74 provided with a shoulder 75 adapted to engage a collar 76, which eng 1 the end of the member 19vand one of the o 18 and is secured to the latter by any suita le means. A collar 78 intsgral with the screw 70 is adapted to engage e end of the bearing 74 to prevent axial movement of the screw. The bearin 74 is held against movement relative to the de 19 by a screw 79 passing through the slide and e the beat'ing. A hand wheel 81 having a Eandle 82 is mounted upon the screw 70 by a keyl 83 in the screw engaging a slot 84 in the w eel. The wheel 81 is held the bushing74 by a nut 85 secured upon the screw 70 and engaging the hub 86 of the wheel.

The annular plate or collar 76, the shoulder 78 on the screw shaft 70, the bushing 74 and the screw 79 hold the cylindrical supporting member 19 inst axial movement in the bearing supports 16 and 17 and hold the screw shaft 70 against axial movement. When the hand wheel 81 is rotated, the nut 71 is moved lengthwise of the hollow support 19 and, due to the connectin pin 72, t e arm 20 moves therewith in a rection transversely of the operative surface of the abrasive wheel 10 or `made of substantially axially of the wheel to carry the dressing tool 53 across the wheel surface.

Considering now the operation of this mechanism, if it is desired to dress the w e'el 10 so that its operative surface is parallel to its axis, the forming bar 27 is first adjusted -so that its surface 45 is parallel to the wheel axis. This is accomplished by turning the thumb nut 35 (Figure 2), the scale 44 indicating the adjustment, and the set screw 43 being first released if necessary. When the screw 43 is tightened down aigu' st the surface 42 of the forming bar it loc the fogtneing bar in the position to which it is ad- ]u The forming'bar having been properly adjusted in position, the hand wheel 63 is now operated to move the dressing tool 53 toward or away from the wheel surface, as may be r uired in order to take a proper cut thev sli e 49 moving to shift the position of the tool 43 relative to the arm 2O when the hand wheel 63 is turned. These adjustments having been made, the hand wheel 81 is now turned and this feeds the dressing tool across the wheel surface to dress the wheel accurately to shape. If it is desired todress the wheel to a tapered form, this is accomplished by first adjusting the position of the forming bar 27 so that its operative surface 45 is out of parallelism with the axis of the wheel,the forming bar bein angular] adjustable with Vrespect; to the wheel axis by operating the thumb nut 35 to swing the forming bar around its end pivot 28.

As man possible embodiments may he e above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

Having I claim as new and desire to secure by Letters Patent is:

1. A grinding machine comprising a grinding wheel, a guard around the wheel, a t mechanism mounted upon the guard inclu ing a support, an arm slidably moun on anda :sys toturnaboutthe axis of the support, a r adjustably carried u n the oppositeend of the arm and arto be pressed against the wheel by the action of gravity, means for the movement of the dresser toward the wheel under the urge of gravity, means for adjusting the position of the dresser relative to said arm towards and from the wheel, and means for causin the dreer to move across the periphery o the wheel along a line substantially parallel to the axis of' the Wheel.

thus described my invention, whatA 2. A grinding machine comprising a grinding wheel, a guard around the whee a t mechanism mounted uponE the guard inclu ing an arm slidably and pivotally secured thereto, a dresser mounted upon the arm so as to permit movement toward the wheel for vengagement therewith, means for sliding the arm relative to the wheel to cause the dresser to move across the periphery of the wheel along a line substantially parallel to the axis of the wheel, and a forming bar mounted upon the guard and adapted to guide the movement of the dresser across the wheel.

3. A grinding machine comprising a grinding wheel, a guard around the wheel, a truing mechanism mounted upon the guard including an arm slidably and pivotally secured thereto, a dresser mounted upon the arm so as to permit movement towards the wheel for engagement therewith, means for moving the arm to cause the dresser to move across the periphery of the wheel along a line substantially parallel to the axis of the wheel, a forming bar adjustably mounted upon the guard to guide the movement of the dresser across the wheel, and means for adjusting the position of the forming bar relative to the axis of the wheel.

Il. In apparatus for truing an abrasive wheel, in combination, a depending supporting arm mounted for movement in a direction substantially axially of the wheel and pivoted to swin toward and away from the wheel surface a out an axis adjacent its upper end, a dressing tool mounted in said arm adjacent its lower end in a position to move into and out of engagement with the wheel surface as said arm swings about its said axis, means for limiting the swinging of said arm, and means for moving said arm to move said tool across the wheel surface.

5. In apparatus for truing an abrasive wheel, in combination, a supporting arm mounted for movement inv a direction'substantially parallel to the axis of the wheel, a dressing tool on said arm adapted to engage the wheel surface, said arm being pivotally mounted to swing toward and away from .the wheel surface and being urged by gravity to swing toward the wheel surface, means for limiting the swinging movement of said arm by gravity, and means for moving said `arm to move said tool across the wheel surface.

6. In apparatus for truing an abrasive wheel, in combination, a supporting arm mounted for movement in a direction substantially parallel to the axis of the wheel, a dressing tool on said arm adapted to engage the wheel surface, said arm being pivotally mounted to swing toward and away from the wheel surface and tending to swing toward the wheel surface to hold said tool in engagement therewith, means for moving said arm to move said tool 'across the wheel surface, and means for limiting the movement of said arm toward the wheel surface 7. In apparatus for truing an abrasive wheel,f1n combination, a supporting arm mounted for movement 1n a direction substantially parallel to the axis of the wheel, a

dressing tool on said arm adapted to engage the wheel surface, said arm being pivotally mounted to swing toward and away from the wheel surface and tending to swing toward the wheel surface to hold said tool in engagement therewith, means for moving said arm to move said tool across the wheel surface, and a forming bar adjustable in position with respect to the wheel axis adapted to limit the movement of said arm toward the wheel surface and to control the path of movement of said tool.

8. In apparatus for truing .an abrasive wheel, in combination, a supporting arm mounted for movement in a direction substantially parallel tothe axis of the wheel, a dressing tool on said arm adapted to engage the wheel surface, said arm being pivotally mounted to swing toward and away from the wheel surface and tending to swing toward the wheel surface to hold said tool in engagement therewith, means for moving said arm to move said tool across the wheel surface, means for limiting the movement of said arm toward the wheel surface, and means for adjusting the position of said tool relative to said arm in a direction toward and away from the wheel surface.

9. A grinding machine, comprising a grinding wheel, a cylindrical support mounted adjacent said wheel, a truing mechanism including an arm slidably and pivotally mounted on said support, a dresser carried by said arm adapted to move across the wheel surface when said arm slides, the center of gravity of said arm being so located in relation to the pivotal axis thereof as to urge said dresser into operative relation with said wheel by the action of gravity, adjustable means for limiting the movement of the dresser toward. the wheel under the urge of gravity, means for sliding said arm along said said support, and means for adjusting the position of the dresser relative to the arm in a direction toward and away from the wheel.

Signed at Detroit, Michigan, this 10th day of August 1926.

HAROLD W. HOLMES. 

